High-hardness and corrosion-tolerant integrated circuit packing mold

ABSTRACT

A high-hardness and corrosion-tolerant integrated circuit packing mold comprises a package mold including at least one filling channel, at least one mold cavity, and at least one channel between the mold cavities; a protecting layer deposited upon surfaces of the package mold and the protecting layer being an amorphous coating layer. In one case, the protecting layer is a graded layer including an amorphous coating layer and a middle layer. In a second case, the protecting layer is a multiplayer structure formed by at least one amorphous coating layer and at least one polycrystal coating layer. In the third case, the protecting layer is a compound structure formed by distributing polycrystal material into an amorphous coating layer.

The present invention is a division application of U.S. patent SeriesNo. 11/172,028, which is assigned to and invented by the inventor of thepresent invention, and thus the contents of the U.S. patent Series No.11/172,028 is incorporated into the present invention as a part of thepresent invention.

The present invention related to the species about the claim 4 in theU.S. patent Series No. 11/172,028.

FIELD OF THE INVENTION

The present invention relates to IC package, and in particular to ahigh-hardness and corrosion-tolerant integrated circuit packing mold,where a protecting layer is adhered to the surface of a package mold soas to protect the package mold from corrosion and wearing.

BACKGROUND OF THE INVENTION

The packaging of integrating circuit starts from the end ofmanufacturing of semiconductors. The object of the packaging is toincrease the bearing and protection functions to protect the ICs fromcorrosion physically and chemically, to provide transferring paths ofenergy and signal distribution of the chips, to prevent the signals fromdelay so as not to affect the function of the system; and to provideheat dissipation path.

Referring to FIG. 1, in the process of IC packaging, the material ismade of epoxy. The epoxy is melt to pass through a filling channel 91.The epoxy passes the filling channel 91 to the mold cavities 93 of thepackage mold 92 and the channel 94 between the mold cavities 93. Afterthe package mold 92 is cooled, the resin will solidified so as topackage the IC substrate and the semiconductors. However, in thepackaging structure of the ICs, the pollution material (general carbide)accumulated on the surface of the mold cavities 93 of the package mold92 and the corrosion on the surfaces of the mold cavities 93 willconfine the lifetime of the package mold 92. Meanwhile, a long time isnecessary to wash the package mold 92.

To improve the packing process, the surface process and design of thechannels of the package mold 92 are important in the packaging of ICs.In one prior art, a protecting layer 95 is electric plated upon thesurface of the package mold 92 with a thickness between 1 to 2 μm. Thematerial of the protecting layer is hard chromium or polycrystalchromium nitride which is coated upon the surfaces of the mold cavities93 so as to have preferred anti-corrosion ability and can be separatedfrom the mold easily. However this prior art has the followingdisadvantages.

In the packaging process of the ICs, the resin will corrode the surfacesof the mold cavities 93 so that the corrosion is dramatic. In general,the Vickers hardness in electrical plating chromium to the protectinglayer is about HV700. The corrosion will induce the viscosity on thesurface of the mold cavities 93. This will reduce the lifetime of thepackage mold 92. Furthermore, a long time for clearing the package mold92 is necessary.

Furthermore, in electrically plating chromium to the package mold 92, ahigh expense is necessary to clear the wasted water and gas in theelectric plating process. Thereby a large operation space is necessary.

To coat nitride chromium to the package mold 92 by vacuum electricplating will have a Vickers hardness of HV1600 to 2000, but theprotecting layer generally has a polycrystal cylindrical structure withworse anti-corrosion ability. Thereby the package mold 92 will be wornby the resin in packaging. Thereby it is difficult to separate from themold.

As adhesive corrosion is formed on the surface of the package mold 92,the package mold 92 must be detached from a punching machine and iswashed by strong acid or strong alkali which will corrode the surfacesof the mold cavities 93 of the package mold 92 with chromium orpolycrystal nitride chromium so as to reduce the lifetime of the packagemold 92.

SUMMARY OF THE INVENTION

Accordingly, the primary object of the present invention is to provide ahigh-hardness and corrosion-tolerant integrated circuit packing mold,where a protecting layer is adhered to the surface of a package mold soas to protect the package mold from corrosion and wearing.

To achieve above objects, the present invention provides a high-hardnessand corrosion-tolerant integrated circuit packing mold comprising: apackage mold including at least one filling channel, at least one moldcavity, and at least one channel between the mold cavities; a protectinglayer deposited upon surfaces of the package mold and the protectinglayer being an amorphous coating layer. In one case, the protectinglayer is a graded layer including an amorphous coating layer and amiddle layer. In a second case, the protecting layer is a multiplayerstructure formed by at least one amorphous coating layer and at leastone polycrystal coating layer. In the third case, the protecting layeris a compound structure formed by distributing polycrystal material intoan amorphous coating layer.

The various objects and advantages of the present invention will be morereadily understood from the following detailed description when read inconjunction with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic view of the prior art.

FIG. 2 is a partial enlarged view of the protecting layer of the priorart.

FIG. 3 is a schematic cross sectional view of the present invention.

FIG. 4 is an enlarged schematic view of the protecting layer of thepresent invention.

FIG. 5 is an enlarged schematic view of the protecting layer of thesecond embodiment of the present invention.

FIG. 6 is an enlarged schematic view of the protecting layer of thethird embodiment of the present invention.

FIG. 7 is an enlarged schematic view of the protecting layer of thefourth embodiment of the present invention.

FIG. 8 is an enlarged schematic view of the compound coating layer ofthe fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In order that those skilled in the art can further understand thepresent invention, a description will be described in the following indetails. However, these descriptions and the appended drawings are onlyused to cause those skilled in the art to understand the objects,features, and characteristics of the present invention, but not to beused to confine the scope and spirit of the present invention defined inthe appended claims.

With reference to FIGS. 3 and 4, the structure of the present inventionis illustrated. The present invention is mainly a package mold 1. Thepackage mold 1 mainly includes a filling channel 10, mold cavities 11,and a channel 12 between the mold cavities 11. The surfaces of thefilling channel 10 and mold cavities 11 and the channel 12 are depositedwith a protection layer by physical vapor deposition (PVD) or chemicalvapor deposition (CVD). The protection layer is an amorphous coatinglayer 21. The amorphous coating layer 21 is mainly made of amorphousmetal oxides (a-Me_(1-x)C_(x)), amorphous metal carbides(a-Me_(1-y)C_(y))), amorphous metal carbide-nitrides (a-Me(C, N))), oramorphous silicon nitrides (a-Si_(1-z)N_(z)), in that the Me (metal) ismainly one of transition metals, such as Cr, Al, Ti, Zr, or otherchemical elements, such as silicon (Si). Furthermore, in abovematerials, x is from 0.3 to 0.7, y is from 0.25 to 0.9, z is from 0.3 to0.8. In this preferred embodiment, the thickness of the amorphouscoating layer 21 is from 0.1 to 0.8 μm, preferably, 0.2 to 0.5 μm.

The amorphous coating layer 21 is not only coated upon the surfaces ofthe filling channel 10 and the mold cavities 11 and the channel 12, butalso it can be deposited on all the upper surfaces 13 of the packagemold 1 so as to protect the package mold 1 not to wear or corroded inthe resin-packaging process.

The amorphous coating layer 21 used on the package mold 1 has a denseamorphous structure so as to increase the ability of anti-corrosion,moreover, the pollution on the channel 12 in the resin-packing process(generally, carbides are accumulated thereon) is reduced. Furthermore,the hardness of the amorphous coating layer 21 is greater than 30 Gpa,which is far higher than the hardness of the prior art coating layer.Thereby when high viscosity and high hardness solidified resins areapplied thereon, the surfaces of the filling channel 10 and moldcavities 11 and the channel 12 are protected from wearing to have theeffect of protecting the package mold 1.

Referring to FIG. 5, the second embodiment of the present invention isillustrated. Those identical to the first embodiment will not describedherein, only those different are described. To have preferred adhesionof the protection coating layer on the package mold 1, the protectinglayer is formed as a graded layer. The surfaces of the filling channel10 and mold cavities 11 and the channel 12 are deposited with a gradedlayer by physical vapor deposition (PVD) or chemical vapor deposition(CVD). In the process, a middle layer 22 is coated thereon firstly andthen an amorphous coating layer 21 is formed. The middle layer 22 isformed by polycrystal or single crystal metals, mainly transition metal,such as Cr, Al, Ti, Zr, or other chemical elements, such as silicon(Si). The middle layer 22 is one of polycrystal metal nitride,polycrystal metal carbides, or polycrystal metal carbide-nitrides. Thethickness of the middle layer 22 is between 0.01 μm to 3 μm, preferablybetween 0.01 μm to 1 μm. Moreover the atom ratios of the nitrogen orcarbon in the polycrystal metal nitride, polycrystal metal carbides ofthe middle layer 22 is between 30% to 80%. The carbide-nitrides in thematerial of the polycrystal metal carbide-nitrides of the middle layer22 is between 30% to 80%. The middle layer 22 is deposited on thesurfaces of the filling channel 10 and mold cavities 11, the channel 12,and all the upper surface 13 of the package mold 1, and an amorphouscoating layer 21 is deposited upon the middle layer 22. The structure,assembly and components of the amorphous coating layer 21 are identicalto those in the first embodiment.

The graded layer in this embodiment causes that the surfaces of thefilling channel 10 and mold cavities 11, the channel 12, and all theupper surface 13 of the package mold 1 have preferred adhesion. Thehardness of the graded layer is greater than 30 GPa. Thereby when highviscosity and high hardness solidified resins are applied thereon, thesurfaces of the filling channel 10 and mold cavities 11 and the channel12 are protected from wearing to have the effect of protecting thepackage mold 1.

Referring to FIG. 6, the third embodiment of the present invention isillustrated. Those identical to the first embodiment will not describedherein, only those different are described. In this embodiment, theprotecting layer is made as a multi-layered coating. The surfaces of thefilling channel 10 and mold cavities 11 and the channel 12 are depositedwith a multi-layered coating layer by physical vapor deposition (PVD) bydifferent metal targets or active gases. The multi-layered coating layerincludes at least one amorphous coating layer 21, and a plurality ofpolycrystal coating layers 23, where the amorphous coating layers 21 andthe polycrystal coating layers 23 are alternatively arranged. Thepolycrystal coating layer 23 is formed by polycrystal metal, mainlytransition metal, such as Cr, Al, Ti, Zr, or other chemical elements,such as silicon (Si). The polycrystal coating layer 23 is one ofpolycrystal metal nitride, polycrystal metal carbides, or polycrystalmetal carbide-nitrides. The thickness of the middle layer 22 is between0.01 μm to 1 μm. Moreover the atom ratios of the nitrogen or carbon inthe polycrystal metal nitride, polycrystal metal carbides of the middlelayer 22 is between 30% to 80%. The polycrystal coating layer 23 isdeposited on the surfaces of the filling channel 10 and mold cavities11, the channel 12, and all the upper surface 13 of the package mold 1,and an amorphous coating layer 21 is deposited upon the polycrystalcoating layer 23. Thickness of the amorphous coating layer 21 is between0.001 μm to 1 μm. The structure, assembly and components of theamorphous coating layer 21 are identical to those in the firstembodiment. The multi-layered structure is not confined to six layersillustrated in FIG. 6. The number of layers are ranged from 1 to 500layers with a thickness from 0.1 μm to 10 μm, preferably from 0.2 μm and0.5 μm.

In this embodiment, the coating layers are formed periodically, such aspolycrystal chromium oxide (Cr_(1-x)N_(x)), amorphous coating siliconnitride (amorphous Si₃N₄). The multi-layered coating layer in thisembodiment causes that the surfaces of the filling channel 10 and moldcavities 11, the channel 12, and all the upper surface 13 of the packagemold 1 have preferred adhesion. The hardness of the graded layer isgreater than 30 GPa. Thereby when high viscosity and high hardnesssolidified resins are applied thereon, the surfaces of the fillingchannel 10 and mold cavities 11 and the channel 12 are protected fromwearing to have the effect of protecting the package mold 1.

Referring to FIGS. 7 and 8, the fourth embodiment of the presentinvention is illustrated. Those identical to the first embodiment willnot described herein, only those different are described. The presentinvention is mainly a package mold 1. The surfaces of the fillingchannel 10 and mold cavities 11 and the channel 12 are deposited with aprotection layer by physical vapor deposition (PVD) or chemical vapordeposition (CVD) by at least two metals or gases (nitrogen orhydrocarbon gas). The protection layer is an amorphous coating layer 21.The amorphous coating layer 21 is mainly a nano-compound formed bydistributing polycrystal material into the amorphous coating layer 21.The polycrystal material is formed by polycrystal metal, mainlytransition metal, such as Cr, Al, Ti, Zr, or other chemical elements,such as silicon (Si). The polycrystal coating layer 23 is one ofpolycrystal metal nitride, polycrystal metal carbides, or polycrystalmetal carbide-nitrides. The sizes of the polycrystal material are aboutseveral nanometer between 5 nm to 10 nm. The thickness of the compoundstructure is between 0.1 μm to 10 μm, preferably between 0.2 to 5 μm.The compound coating layer has a size of nanometers and formed bypolycrystal chromium nitride and amorphous silicon nitride. Thepolycrystal chromium nitride is distributed in the amorphous siliconnitride.

In this embodiment, the compound coating layer in this embodiment causesthat the surfaces of the filling channel 10 and mold cavities 11, thechannel 12, and all the upper surface 13 of the package mold 1 havepreferred adhesion. The hardness of the graded layer is greater than 30GPa. Thereby when high viscosity and high hardness solidified resins areapplied thereon, the surfaces of the filling channel 10 and moldcavities 11 and the channel 12 are protected from wearing to have theeffect of protecting the package mold 1.

Moreover the atom ratios of the nitrogen or carbon in the polycrystalmetal nitride, polycrystal metal carbides of the middle layer 22 isbetween 30% to 80%. The polycrystal coating layer 23 is deposited on thesurfaces of the filling channel 10 and mold cavities 11, the channel 12,and all the upper surface 13 of the package mold 1, and an amorphouscoating layer 21 is deposited upon the polycrystal coating layer 23.Thickness of the amorphous coating layer 21 is between 0.001 μm to 1 μm.The structure, assembly and components of the amorphous coating layer 21are identical to those in the first embodiment. The multi-layeredstructure is not confined to six layers illustrated in FIG. 6. Thenumber of layers are ranged from 1 to 500 layers with a thickness from0.1 μm to 10 μm, preferably from 0.2 μm and 0.5 μm.

The present invention is thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

1. A high-hardness and corrosion-tolerant integrated circuit packingmold comprising: a package mold including at least one filling channel,at least one mold cavity, and at least one channel between the moldcavities; a protecting layer deposited upon surfaces of the package moldand the protecting layer being an amorphous coating layer.
 2. Thehigh-hardness and corrosion-tolerant integrated circuit packing mold asclaimed in claim 1, wherein the protecting layer is a graded layerincluding an amorphous coating layer and a middle layer.
 3. Thehigh-hardness and corrosion-tolerant integrated circuit packing mold asclaimed in claim 1, wherein the protecting layer is a compound structureformed by distributing polycrystal material into an amorphous coatinglayer.
 4. The high-hardness and corrosion-tolerant integrated circuitpacking mold as claimed in claim 1, wherein the protecting layer iscoated on the filling channel, mold cavities, channels and uppersurfaces of the package mold.
 5. The high-hardness andcorrosion-tolerant integrated circuit packing mold as claimed in claim1, wherein the protecting layer is made by one of physical vapordeposition (PVD) or chemical vapor deposition (CVD)
 6. The high-hardnessand corrosion-tolerant integrated circuit packing mold as claimed inclaim 1, wherein the protection layer is an amorphous coating layer; theamorphous coating layer is mainly made of one of amorphous metal oxides(a-Me_(1-x)C_(x)) with x is between 0.3 to 0.7; amorphous metal carbides(a-Me_(1-y)C_(y))) with y between 0.25 to 0.9, and amorphous metalcarbide-nitrides (a-Me(C, N))), or amorphous silicon nitrides(a-Si_(1-z)N_(z)) with z between 0.3 to 0.8, wherein x, y, and z areatomic ratio, in that the Me (metal) is one of transition metals.
 7. Thehigh-hardness and corrosion-tolerant integrated circuit packing mold asclaimed in claim 1, wherein the hardness of the protecting layer isgreater than 30 GPa.
 8. The high-hardness and corrosion-tolerantintegrated circuit packing mold as claimed in claim 1, wherein and thethickness of the amorphous coating layer 21 is selected from a valuebetween 0.1 μm to 10 μm or a value between 0.2 μm and 0.5 μm.
 9. Thehigh-hardness and corrosion-tolerant integrated circuit packing mold asclaimed in claim 2, wherein the graded layer is formed by coating amiddle layer on a surface of the package mold and then an amorphouscoating layer is coated upon the middle layer.
 10. The high-hardness andcorrosion-tolerant integrated circuit packing mold as claimed in claim2, wherein a thickness of the middle layer is between 0.01 μm to 3 μm.11. The high-hardness and corrosion-tolerant integrated circuit packingmold as claimed in claim 2, wherein the middle layer is a silicon layer.12. The high-hardness and corrosion-tolerant integrated circuit packingmold as claimed in claim 2, wherein the middle layer is one of apolycrystal metal layer, polycrystal metal nitride, a polycrystal metalcarbide, and a polycrystal metal carbide-nitride; where the metal is oneof transition metals.
 13. The high-hardness and corrosion-tolerantintegrated circuit packing mold as claimed in claim 3, wherein the sizeof the polycrystal material is between 5 nm to 100 nm (nanometers). 14.The high-hardness and corrosion-tolerant integrated circuit packing moldas claimed in claim 3, wherein the polycrystal material is selected fromone of silicon, polycrystal metals, polycrystal metal nitrides,polycrystal metal carbides, and polycrystal metal carbide-nitrides,where the metal is one of transition metals.
 15. The high-hardness andcorrosion-tolerant integrated circuit packing mold as claimed in claim6, wherein the transition metal is selected from one of chromium,aluminum, and zirconium.
 16. The high-hardness and corrosion-tolerantintegrated circuit packing mold as claimed in claim 12, wherein thetransition metal is one selected from chromium, aluminum, zirconium. 17.The high-hardness and corrosion-tolerant integrated circuit packing moldas claimed in claim 14, wherein the transition metal is one selectedfrom chromium, aluminum, zirconium.
 18. The high-hardness andcorrosion-tolerant integrated circuit packing mold as claimed in claim12, wherein the ratio of the nitrogen atom in the polycrystal metalnitride is from 30% to 80%; and the ratio of the carbon atom in thepolycrystal metal carbide is from 30% to 80%.
 19. The high-hardness andcorrosion-tolerant integrated circuit packing mold as claimed in claim14, wherein the ratio of the nitrogen atom in the polycrystal metalnitride is from 30% to 80%; and the ratio of the carbon atom in thepolycrystal metal carbide is from 30% to 80%.